Roll-to-roll printing is commonly used to produce a plurality of images on a single length of media. In roll-to-roll printing, a length of media in the form of a print substrate is fed from an input roll to a printing device. The printing device prints images on the substrate and the substrate is then fed to an output roll.
One application for roll-to-roll printing is the flexible packaging industry (e.g., packaging for chips or other snacks). In some applications of flexible packaging printing is done on very thin films. When the thickness of the ink layer printed on the substrate is substantial (e.g., the thickness of the ink layer approaches the thickness of the substrate), it can introduce distortion to the output roll which may disrupt normal operations. In particular, if the cumulative pile height of the printed ink is not relatively consistent across the roll, one side or a portion of the output roll may become unbalanced. For example, if an image printed on the right side of a substrate contains substantial content, while the image printed on the left side of the substrate contains only limited content, the right side of the substrate will have a greater cumulative pile height and the output roll will end up with a greater circumference than the left side of the output roll. In addition, the right side of the roll will tend to be taut while the left side of the roll will tend to be loose. When the same or similar image is repeatedly printed, as is typically the case with roll-to-roll printing, this repetition only magnifies the pile height problem at the output roll. Distortion in the output roll creates problems during both the printing process and downstream in the packaging process.
In view of the foregoing, it would be advantageous to provide a method of printing images to compensate for pile height differentials.